JP2000046575A - Navigation apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To calculate an optimum route by detecting an actually traveled road, updating travel frequency data corresponding thereto, and calculating the route cost, based on the frequency when a destination is inputted. SOLUTION: A departure point and destination point are determined and the route searching start is requested through an input unit 11. CPU 4 processes the route search to newly extract a new road ID as a candidate from route retrieving data. The road ID exists in an SRAM 7, the cost of the road ID about its route data is reduced below a usual cost, based on the travel frequency. If not in the SRAM 7, the true cost of the route retrieving data for the road ID is read. Based on the cost corresponding to such extracted road ID, the cumulative cost from the departure point is obtd. About all candidate roads in an objective area of this route search, whether the extraction is finished is checked and if not finished, this is repeated, but if finished, an optimum route with the lowest cumulative cost is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an in-vehicle navigation device which draws a vehicle position detected by a vehicle position detecting means using map data at a corresponding position on a map image. In particular, the present invention relates to a vehicle navigation device that utilizes the traveling frequency for each road for route calculation.

[0002]

2. Description of the Related Art A vehicle navigation device is a map data storage device such as a CD-ROM or an IC memory card storing map data, a display device, a GPS receiver, a traveling distance sensor, and a current position of a vehicle such as a direction sensor. Has a vehicle position detecting device for detecting the vehicle position, reads map data including the current position of the vehicle from a CD-ROM or the like, draws a map image centered on the vehicle position based on the map data, and displays the map image on the display screen At the same time, the vehicle position mark is fixed at a predetermined position on the display screen, and the map image is scrolled and displayed in accordance with the movement of the vehicle, or the map image is fixed on the screen and the vehicle position mark is moved, so that the vehicle is moved. You can see at a glance where you are currently driving.

[0003] In order to smoothly drive on unfamiliar roads, a destination is input and the road to be traveled to the destination is determined by the CD-RO.
A function of calculating a route based on road data such as intersection data and node data of M and performing route guidance based on the result (hereinafter, referred to as a route guidance function) is provided.

In this route guidance function, a route search database is stored in a CD together with road data and map data.
-Stored in a ROM, for example, to search for a route to a destination that can be reached in the shortest distance, and display the searched route on a screen to provide guidance.

In the route search database, a portion where a road such as an intersection intersects a road is called a node, and a link between the nodes is called a link. A link L shown in FIG. 7 has a direction from a node LO to a node L1. Saved as a link.
Also, links usually have pre-calculated costs,
Alternatively, there is information on distance, road class, and road width.

The route calculation is performed, for example, in Japanese Patent Laid-Open No. 2-172000.
As described in Japanese Patent Laid-Open Publication No. H10-163, the cost is calculated during the route search, and is basically calculated using the algorithm of the Dijkstra method or its application. For example, a node within a predetermined range connecting the departure place and the destination and a link connecting adjacent nodes corresponding to the road between the intersections are combined, and the cost assigned to each node is integrated.
This cost is set in advance according to the road level such as a national road, a metropolitan road, a prefectural road, and a city road, the width of the road, and the like. The route with the lowest integrated value is selected.

[0007]

However, the above-mentioned conventional navigation apparatus has the following problems. That is, since the cost used for the route calculation is determined by the road level, the road width, and the like, the result of the route calculation using this cost does not always select a road that is easy for the user to run or a road that the user is familiar with. There is no case. In particular, despite the fact that the roads that the user frequently runs and the roads that he or she knows well are the target roads for calculation, the roads are expensive because of the narrow road width, etc. The result is that it is not chosen for the road.

Further, as shown in FIG. 8, the result of a route search between the departure place O and the destination D becomes a route A, and the user actually wants to travel on the X road and go to the destination. In this case, even if the route deviates from route A and the route of origin is recalculated as O ', if the cost of road X is high relative to the surrounding road, the result is that road X is not selected as shown in FIG. However, the route calculation result is very unpleasant for the user.

An object of the present invention is to provide a road which is easy for the user to run, or a road which the user is familiar with.
Focusing on the fact that the user travels frequently, stores the roads that frequently travel, and also stores the travel frequency and related route search data. In the route search, the stored route search data is stored. It is an object of the present invention to provide a navigation device having a route calculation function that reduces costs and facilitates selection in a route search.

[0010]

In order to achieve the above object, the invention according to claim 1 is a storage means for storing road data, traveling frequency data corresponding to each road, and cost data corresponding to each road. Means for detecting the current location of the vehicle, frequency updating means for detecting the road on which the vehicle has actually traveled, and updating travel frequency data corresponding to the road on which the vehicle has actually traveled, and inputting a destination based on the frequency. Route calculation means for calculating the calculated route cost and calculating the optimum route to the destination.

According to the first aspect of the present invention having the above configuration, the following operation can be obtained. In other words, the cost of the route search data is updated and stored at a low cost for a road that has actually traveled frequently, so that a route search result based on the past travel route that has actually traveled can be obtained. Route guidance that matches the taste of

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a navigation device according to the present invention will be described below with reference to the drawings. Each function of the embodiment described below is realized by a predetermined mechanism or software controlling a computer and a peripheral device. The invention and the embodiments have been described assuming virtual circuit blocks such as ". Therefore, each hardware element or software element that realizes this for each block does not correspond one-to-one.

[1. Configuration] FIG. 1 is a block diagram showing a configuration of a vehicle-mounted navigation device according to a first embodiment of the present invention. In FIG. 1, reference numeral 1 denotes an absolute position detection unit, which is configured by, for example, a GPS (Global Positioning System) receiver, and detects the latitude / longitude of the current position of the vehicle, that is, position data, based on a signal received by an antenna. It has become. Reference numeral 2 denotes a relative azimuth detecting unit,
It detects a change in azimuth accompanying the traveling of the own vehicle,
For example, it is constituted by a geomagnetic sensor or a gyro. Reference numeral 3 denotes a vehicle speed detection unit that detects the speed of the own vehicle.

A display unit 10 has a display screen such as a CRT or a liquid crystal display, and displays an initial setting menu, a road map, a mark indicating a vehicle position, a recommended route, and the like on the display screen. I do. Reference numeral 11 denotes an input unit, which includes a key input remote controller or the like, or is configured as a touch panel provided on a display screen of the display unit 10. The input unit 11 allows the driver to set a destination and parameters required for route calculation (hereinafter, referred to as route mode) at the time of initial setting. Reference numeral 9 denotes a user interface unit that connects the display unit 10 and the input unit 11 with a CPU 4 described later.

Reference numeral 12 denotes a CD-ROM, which stores map data including various road information such as intersection position data.
Specifically, this map data is obtained by dividing a Japan road map into a mesh shape, and includes road data composed of a combination of nodes and links for each mesh unit, and background data of buildings and the like. Here, a node is a point that divides a road into a number of sections, and a route connecting the nodes is a link.
A CD-ROM controller 12a reads map data from the CD-ROM 12.

Reference numeral 5 denotes a ROM accessed by a main CPU 4 described later at the time of startup, and also stores a program for calculating a route and the like. Reference numeral 6 denotes a dynamic RAM (DRAM) for loading a main program. Reference numeral 7 denotes a non-volatile memory, which is configured by, for example, backing up an SRAM with a battery or the like. The nonvolatile memory 7 is backed up by a battery or the like even when the power is turned off, and stores and holds a road ID, a driving frequency, route data on the road, and the like even when the power is turned off. Reference numeral 8 denotes a VideoRAM (VRAM) provided for the display unit 10. 13
Is an FM for extracting desired data from FM broadcast waves
A multiplex broadcast receiving and processing unit.

The route data database stored in the non-volatile memory 7 classifies each road according to the traveling direction as shown in FIG. 2 so that the link cost can be changed during the route search. Individual road ID
. Are added. The driving frequency data 102 is further associated with these individual road IDs.
a, 103a... and route search data 102
a, a road database with 103a ...
By storing, the cost can be changed depending on the driving frequency during the route search.

In FIG. 1, reference numeral 4 denotes a main CPU, at least a route calculation processing unit 14, a map matching processing unit 15,
In addition, a traveling frequency processing unit 16 is provided.

The map matching processing section 15 includes an estimated position estimated from azimuth data and speed data detected by the relative azimuth detecting section 2 and the vehicle speed detecting section 3, and a positioning position detected by the absolute position detecting section 1. While collating
A process is performed to identify the current road ID and the current position on the road, and to match the current position of the vehicle to be displayed on the position display screen with the road on the map.

If the map matching processor 15 determines that the vehicle is traveling on the road ID-X, the traveling frequency processor 16 sets the route search data corresponding to the road ID-X and the traveling frequency to 1 and executes the processing shown in FIG. In the memory. Also,
It is determined whether or not the current road ID has traveled in the past, and if it is determined that the vehicle has traveled in the past, 1 is added to the road traveling frequency. In the example of FIG. 3, the road ID 102 indicates that the vehicle has traveled 15 times.

In the route search, the route search processing unit 14 calculates the cost of the route search data stored in the non-volatile memory at a low cost, taking into consideration the traveling frequency.

[2. Operation and Effect] The operation of the present embodiment configured as described above will be described with reference to the flowcharts shown in FIGS.

FIG. 4 is a flowchart for storing the road ID and the driving frequency in the memory. The memory for storing the road ID, the driving frequency, and the route data related to the road is stored in a nonvolatile memory such as an SRAM as described above. In step 1, traveling on the road is confirmed, and the vehicle has a road ID of X.
If it is determined that the vehicle is traveling on the road,
It is determined whether X exists in the road ID stored in AM. If X is already stored in the SRAM as the road ID, 1 is added to the driving frequency of the road ID in step 3. If not, go to Step 4 for road ID and driving frequency
1. The related path data is newly stored in the SRAM.

FIG. 5 shows a flowchart for selecting a route search function in consideration of the frequency of road travel. When a destination setting operation is performed by the input unit 11, it is first checked in step 5 whether a route calculation in consideration of the driving frequency has been set. It is assumed that this is selected by the section and registered in the SRAM 7, etc. If the route calculation considering the driving frequency is set, the route search processing in FIG. If the calculated route calculation is not set, a route search based on the true cost of the map search database is performed in step 7.

FIG. 6 is a flowchart showing an outline of a route search process in consideration of the traveling frequency. When the departure place and the destination are determined, and the start of the route search is requested from the input unit 11, the CP
U4 performs the calculation using the route search algorithm outlined below.

First, in step 8, the ID of a road newly extracted as a candidate by the route search processing is extracted from the route search data. Road ID extracted in step 9
Is on the SRAM 7. If SRAM7
If it is above, in step 10, the cost of the road ID related to the route data is made lower than the normal cost based on the driving frequency.

As a method of reducing the cost, for example, the following correction calculation is performed with the maximum running frequency as MAX. The coefficient α is O <α <1.0, and is a parameter that can be reduced to the maximum with respect to the route data. COST = cost−α * (cost * driving frequency / MAX) (cost is the true cost of the road data stored as an initial value in the route search data)

In step 9, the extracted road ID is set to SR
If it is not on the AM 7, in step 11, the true cost of the route search database for the extracted road ID is read. When the costs are extracted in steps 10 and 11, the integrated cost from the departure point is obtained based on the cost corresponding to the newly extracted road ID in step 12. Subsequently, in step 13, it is checked whether extraction has been completed for all the candidate roads in the current route search target area, and if not, steps 8 to 12 are repeated again. If all the extractions have been completed, in step S14, an optimal route with the lowest integrated cost is selected from the candidate routes from the starting point to the destination.

[3. Other Embodiments] The present invention is not limited to the above-described embodiments, but also includes the following other embodiments. That is, as the traveling frequency, instead of simply counting the number of times of passage, the date and time data may be registered with the number of times of passage, and the count may be subtracted, for example, for one month from the registration, and the number of times of passage within a predetermined period may be used. . Further, the nonvolatile memory is not limited to the above-described SRAM, and may be an EEPROM or the like that does not require a power supply backup.

[0030]

As described above, according to the present invention,
By reducing the cost of the route search data for a road with a high frequency of travel, it is easier to obtain a route search result on a road with a high frequency of travel. A road with a high traveling frequency can be regarded as a road that is easy for the user to run or a road that the user knows well, so that the route calculation result can include the road desired by the user.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a navigation device according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a road database according to the embodiment;

FIG. 3 is a diagram showing a road database structure according to the embodiment;

FIG. 4 is a flowchart of storing a road ID and a driving frequency in a memory according to the embodiment;

FIG. 5 is a flowchart for selecting a route search function in consideration of a road traveling frequency in the embodiment;

FIG. 6 is a flowchart of an outline of a route search process in consideration of a traveling frequency in the embodiment.

FIG. 7 is a diagram for explaining an example of a general route search database.

FIG. 8 is a diagram for explaining a route from a starting point O to a destination D.

FIG. 9 is a diagram for explaining a route from a departure place O ′ to a destination D.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Absolute position and direction detection part 2 ... Relative direction detection part 3 ... Vehicle speed detection part 4 ... Main CPU 7 ... SRAM 9 ... User interface part 10 ... Display part 11 ... Input part 12 ... CD-ROM 12a ... CD-ROM control Unit 14: route calculation processing unit 15: map matching processing unit 16: traveling frequency processing unit

Claims (1)

[Claims] A storage means for storing road data, travel frequency data corresponding to each road, and cost data corresponding to each road; a means for detecting a current location of a vehicle; Frequency updating means for updating the driving frequency data corresponding to the road actually traveled, and route calculating means for calculating a route cost based on the frequency by inputting a destination and calculating an optimal route to the destination And a navigation device.